Nitridation of InP(1 0 0) surface studied by synchrotron radiation

TL;DR

This study investigates the nitridation process of InP(1 0 0) surfaces using synchrotron radiation, revealing the formation of indium nitride layers and their stability at high temperatures through surface chemical analysis.

Contribution

It provides a detailed analysis of indium nitride formation on InP surfaces via synchrotron radiation and introduces a theoretical model for layer thickness estimation.

Findings

Indium nitride layers of nearly two monolayers are formed.

The nitridated surface remains stable up to 450°C.

Nitridation involves reaction of indium clusters with nitrogen, reducing metallic indium bonds.

Abstract

The nitridation of InP(1 0 0) surfaces has been studied using synchrotron radiation photoemission. The samples were chemically cleaned and then ion bombarded, which cleaned the surface and also induced the formation of metallic indium droplets. The nitridation with a Glow Discharge Cell (GDS) produced indium nitride by reaction with these indium clusters. We used the In 4d and P 2p core levels to monitor the chemical state of the surface and the coverage of the species present. We observed the creation of In-N and P-N bonds while the In-In metallic bonds decrease which confirm the reaction between indium clusters and nitrogen species. A theoretical model based on stacked layers allows us to assert that almost two monolayers of indium nitride are produced. The effect of annealing on the nitridated layers at 450 $^\circ$C has also been analysed. It appears that this system is stable up to this temperature, well above the congruent evaporation temperature (370 $^\circ$C) of clean InP(1 0 0): no increase of metallic indium bonds due to decomposition of the substrate is detected as shown in previous works [L. Bideux, Y. Ould-Metidji, B. Gruzza, V. Matolin, Surf. Interface Anal. 34 (2002) 712] studying the InP(1 0 0) surfaces.